Logo
FULL SITE MENU

Cruising RPMs

P

pinprod

New member
My boat seem to run very well

My boat seem to run very well at 4000 RPMs. 6.2MPI Bravo 3. Is 4000 a engine safe RPM for long term Cruising
 
"Thats not bad for cruising.

"Thats not bad for cruising.
Usual cruising range is from 3000 to 4000 rpm.
Your max rpm is 5200, so you are comfortably in the sweet spot.
What sort of fuel consumption do you get at that cruise speed?

Rod"
 
Maybe I'm wrong but it see

Maybe I'm wrong but it seems high for a BB. My 4 banger cruises it's most efficeint at 3400-3800 in a 19'. Guys I know with small bloack V-8s usually cruise at around 2500-2800 but that's in boats over 22'. Seems like you would be burning a lot of fuel at 4K.
 
"Assuming you meant 4000 rpms

"Assuming you meant 4000 rpms you're burning about 13.5 GPH. I'm not familiar with big block fuel economy but I bet if you backed off the rpms to 3200 - 3400 you drop your consumption quite a bit. ~10 GPH seems doable. But it all depends on how expensive gas is to you. If I was burning that kind of fuel I don't think my wife would let me keep the boat! 13.5 GPH @ $4.95/gal, that's $66/hour! I don't even make that much.

My buddy in the SF Bay area has a 24' Searay with a 5.7L SB and @ 2800-3000rpms he's burning about 9-10 GPH and he's got a pretty heavy boat and there is always a head wind and strong tides. Just a reference.

I guess to answer your question it's safe but not very efficient."
 
"Richard;
Must be a heavy boa

"Richard;
Must be a heavy boat to be only making 27 mph @ 4000 rpm.
Also, unless I missed something the 6.2L is a small block. Big blocks start at 7.4 L and up.
The 6.2 is actually a small block chevy 350 with a 400 crankshaft. It has a 4.030" bore and a 3.75" stroke. You wind up with 383 cu in displacement. (Sounds like a Chrysler engine size; but isn't)

Rod"
 
Back
Top